Stephen Toub - MSFT

Partner Software Engineer, .NET

Stephen Toub is a developer on the .NET team at Microsoft.

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Implementing a simple ForEachAsync, part 2

March 5th, 2012
After my previous post, I received several emails and comments from folks asking why I chose to implement ForEachAsync the way I did.  My goal with that post wasn’t to prescribe a particular approach to iteration, but rather to answer a question I’d received… obviously, however, I didn’t provide enough background...

Implementing a simple ForEachAsync

March 4th, 2012
Jon Skeet recently asked me how I might go about implementing the following “asynchronous ForEach” behavior: Given what we now know about SemaphoreSlim from my previous post, here’s one way to achieve this: public static Task ForEachAsync<TSource, TResult>(     this IEnumerable<TSource...

Visual Studio 11 Beta currently incompatible with AsyncCtpLibrary*.dll

March 3rd, 2012
The C# and Visual Basic compilers implement support for async/await by generating code that utilizes some specific types in the underlying framework.  These types include the “awaiters” used to await things (like Tasks) as well as the “builders” used in handling the lifetime of an async method’s invocation. ...

“The Zen of Async” at the MVP Summit 2012

March 3rd, 2012
Thanks to everyone who attended my "The Zen of Async" presentation on Thursday at the MVP Summit.  As I've had several requests, here are the slides and code for the talk. Toub_MVPSummit2012_ZenOfAsync.zip...

What’s New for Parallelism in .NET 4.5 Beta

February 29th, 2012
At //BUILD/ in September, we blogged about the wealth of new support available for parallelism in the .NET Framework 4.5 Developer Preview.  Since then, we’ve been hard at work on the .NET 4.5 Beta.  With the beta just released, here are a few interesting and related things that are new or have changed since the Developer ...

Building Async Coordination Primitives, Part 7: AsyncReaderWriterLock

February 12th, 2012
In my last past, we looked at building an AsyncLock in terms of an AsyncSemaphore.  In this post, we’ll build a more advanced construct, an asynchronous reader/writer lock.An asynchronous reader/writer lock is more complicated than any of the previous coordination primitives we’ve created.  It also involves more policy, ...

Building Async Coordination Primitives, Part 6: AsyncLock

February 12th, 2012
Last time, we looked at building an AsyncSemaphore.  Here, we’ll look at building support for an async mutual exclusion mechanism that supports scoping via ‘using’.As mentioned in the previous post, semaphores are great for throttling and resource management.  You can give a semaphore an initial count of the number ...

Building Async Coordination Primitives, Part 5: AsyncSemaphore

February 12th, 2012
In my last few posts, I covered building an AsyncManualResetEvent, an AsyncAutoResetEvent, an AsyncCountdownEvent, and an AsyncBarrier.  In this post, I’ll cover building an AsyncSemaphore class.Semaphores have a wide range of applicability.  They’re great for throttling, for protected access to a limited set of resources...

Building Async Coordination Primitives, Part 4: AsyncBarrier

February 11th, 2012
Last time, we looked at building an AsyncCountdownEvent.  At the end of the post, I highlighted a common pattern for using such a type, which is for all of the participants to signal and then wait for all of the other participants to signal as well.  This kind of synchronization is typically referred to as a “barrier,” ...

Building Async Coordination Primitives, Part 3: AsyncCountdownEvent

February 11th, 2012
In my last two posts, I discussed building AsyncManualResetEvent and AsyncAutoResetEvent coordination primitives.  In this post, I’ll build on that to create a simple AsyncCountdownEvent.A countdown event is an event that will allow waiters to complete after receiving a particular number of signals.  The “countdown&rdquo...